Modular panoramic night vision goggles

ABSTRACT

A modular binocular-like vision assembly ( 300 ) has individual interconnecting inner ( 320, 330 ) and outer ( 310, 340 ) optical modules. Each module is separately sealed and self-contained and includes image intensifier means for converting incoming light to an intensified visible image for presentation to the eyes of the observer in low light conditions. Electrical connectors are provided between the modules for permitting free flow of electrical power and information between the modules. Attaching system is provided for removably attaching the outer modules to the inner modules to deliver a panoramic field of vision and removal of any single module from the assembly will not break any pressure seals or degrade the optical performance of the removed module or the remaining modules.

RELATED APPLICATION

[0001] This application claims priority on a U.S. provisional patentapplication, U.S. Serial No. 60/232,720, titled MODULAR PANORAMIC NIGHTVISION GOGGLES, filed Sep. 15, 2000.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to a modular, binocular-type viewingsystem having a substantially enlarged field of view that can be usedpreferably in low light and low gravity conditions and that comprisesseparate modular elements, including separate optical, camera and HUDmodules.

[0004] 2. Discussion of Related Art

[0005] Existing night vision systems have many applications in every daylife. Perhaps the most well known use for night vision systems is by themilitary when performing nighttime maneuvers. The night vision systemspermit vision under very low light conditions by converting incominginfrared and/or visible light from a viewed scene to an intensifiedvisible light image. During nighttime maneuvers, military personnel areoften performing other tasks, such as piloting an aircraft or driving avehicle, which require the freedom of their hands while they arescanning the territory. Accordingly, night vision systems have beendeveloped to be worn upon the head of a user, such as goggles beingsecured directly on the head or by being mounted to a helmet or a visor.

[0006] Placing a night vision system on the head of a user placessignificant constraints upon the optical design of the system. Forexample, goggles worn upon the head of a user must be both compact andlight in weight because excessive weight or front-to-back length of thegoggles can cause the goggles to exert large moments on the user's headcausing severe instability problems and preventing their effective usein applications in which the user's head may be subjected to highgravitational or centrifugal loads. Furthermore, in a wide field of viewoptical system, the focal length of the eyepiece optics must beshortened correlatively that of the wide angle objective for unitymagnification; and, in night vision goggles, this results ininsufficient eye relief between the eyepiece optics and the eye, whichnot only causes discomfort to the user, but also interferes with theability to position a helmet visor, eyeglasses and other structuresbetween the goggles and the eyes of the user. In order to compensate forinadequate eye relief, prior night vision goggles have generally beenlimited to providing a field of view of no more than about 40 degrees.

[0007] Night visions goggles have been used in military aviation forseveral years with fields of views ranging from 30 degrees (Early Cat'sEyes night vision goggles from GEC-Marconi Avionics) to 45 degrees(NITE-OP and NITE-Bird night vision goggles, also from GEC-MarconiAvionics). The vast majority of night vision goggles used in militaryaviation have a 40-degree field of circular view (AN/AVS-6 andAN/AVS-9). A major limitation of such prior art devices is thatincreased field of view could only be obtained at the expense ofresolution since each ocular uses only a single image intensifier tubeand each image intensifier tube has a fixed number of pixels. Therefore,if the fixed numbers of pixels is spread over a larger field of view,then the angular subtense per pixel increases, which translates intoreduced resolution. Understandably increased field of view is a majorenhancement desired by military aviators, closely followed byresolution. In conventional goggles, both eyes also typically see thesame field of view, i.e., there is a 100-percent overlap of the imageviewed by both eyes of the observer. Such a limited field of viewgreatly restricts the effectiveness of the night vision apparatus.

[0008] U.S. Pat. No. 5,229,598 addresses the above-mentioned problemsand discloses a compact, lightweight, night vision system capable ofproviding an enlarged field of view of up to 60 degrees with improvedvisual acuity and sufficient eye relief.

[0009] In addition to night vision systems, other imaging systems, suchas hand-held binoculars, typically provide a rather limited field ofview; and it would be desirable to provide such systems with increasedfields of view as well. Individually sealed and self-containedconstituent modular elements capable of providing some of theabove-desired features, respectively, would enable such an imagingsystem to be built incrementally as desired.

SUMMARY OF THE INVENTION

[0010] The present invention regards a modular, binocular-like visionsystem for enabling an observer to view an object. The system includesan input end that receives light from the object and an optical transfersystem that receives the light received from the input end and transfersthe received light to an image intensifier which intensifies thereceived light, wherein the intensified received light is transferred toand transmitted out of an output end of the system, wherein the lighttransmitted out of the output end forms a field of view of the objectthat is greater than a 60-degree horizontal field of view.

[0011] Another aspect of the present invention regards a binocular-likevision system for enabling an observer to view an object. The systemincludes a first optical component having a first input end thatreceives light from the object and a first output end that receiveslight from the first input end, wherein the first output end defines afirst optical axis along which light received from the first input endis transmitted. A second optical component having a second input endthat receives light from the object and a second output end thatreceives light from the second input end, wherein the second output enddefines a second optical axis along which light received from the secondinput end is transmitted. A third optical component comprising a thirdinput end that receives light from the object and a third output endthat receives light from the third input end, wherein the third outputend defines a third optical axis along which light received from thethird input end is transmitted, wherein light transmitted along thefirst, second and third optical axes forms a field of view comprising afirst portion having a monocular effect on the observer and a secondportion having a binocular effect on the observer.

[0012] Another aspect of the present invention regards a binocular-likevision system for enabling an observer to view an object. The systemincludes a first optical component having a first input end thatreceives light from the object and a first output end that receiveslight from the first input end, wherein the first output end defines afirst optical axis along which light received from the first input endis transmitted. A second optical component having a second input endthat receives light from the object and a second output end thatreceives light from the second input end, wherein the second output enddefines a second optical axis along which light received from the secondinput end is transmitted. A third optical component having a third inputend that receives light from the object and a third output end thatreceives light from the third input end, wherein the third output enddefines a third optical axis along which light received from the thirdinput end is transmitted, wherein light transmitted along the first,second and third optical axes is simultaneously transmitted from thebinocular-like vision system to the observer.

[0013] In a further preferred embodiment of this invention, a panoramicnight vision goggle (PNVG) is provided that, like the previousembodiment, features a partial overlap 100-degree horizontal by40-degree vertical intensified field of view. Again, the central30-degree horizontal by 40-degree vertical field of view is completelybinocular, while the right 35 degrees is still seen with the right eyeonly and the left 35 degrees is viewed by the left eye only.Additionally, a thin line of demarcation separates the binocular scenesfrom the outside monocular scenes. This embodiment also utilizes thenewly developed 16-mm image intensifier tube, dual fixed eyepieces,which are tilted and fused together, and four objective lenses, theinner two being adjustable and the outer two being fixed. The inneroptical channels are not folded and are designed with fast F/1.05objective lenses. The outboard channels use the folded inner channeloptics design with F/1.17 objective lenses. The effective focal lengthof the eyepiece is 24.0 mm, while the physical eye clearance has beenincreased to 27 mm. All of the mechanical adjustments currently used onthe AN/AVS-6 and AN/AVS-9 are the same (i.e., tilt, independentinter-pupilary distance adjustment, up/down, and fore/aft). This furtherembodiment may also be equipped with a heads-up display (HUD) ifdesired.

[0014] In yet another embodiment, the PNVG goggle is designed so thatthe individual optical channels are modular and thus detachable fromeach other. Each optical channel is a separately sealed andself-contained module. Removal of any single module from the PNVGassembly will not break any pressure seals or degrade the opticalperformance of the removed module or the remaining modules. Electricalpower and information (i.e., data signals and the like) required by amodule is provided through electrical connectors provided between themodules. The modules include means of attachment that ensures properpositioning and alignment of the adjacently mating modules. In apreferred embodiment, an integral electrical connector is containedwithin each module that enables the electrical connection betweenadjacent modules to be made simultaneously with the mechanicalattachment of the module.

[0015] In addition to the modularity of the four primary opticalchannels of the PNVG assembly, the display (i.e., HUD) and camera aremodular as well. Similar to the individual optical modules, each ofthese components are separately sealed and self-contained modules aswell. Removal of the camera or display will not break any pressure sealsor degrade the performance of the removed module or the remainingmodules. Again, electrical power and information (i.e., data signals andhe like) required by the camera or display is provided by electricalconnectors means provided on each module.

[0016] Thus, in aone preferred embodiment, this invention presents anapparatus that significantly increases the field of view of night visiongoggles utilizing four modular optical components to produce a panoramicfield of vision. This invention also presents the advantage of providingan enlarged field of view with improved visual acuity and sufficient eyerelief for a compact, lightweight, modular, binocular-like visionsystem.

[0017] Further advantages and specific details of the invention will beset forth hereinafter in conjunction with the following detaileddescription of presently preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a top view of a binocular-like vision system accordingto the present invention;

[0019]FIG. 2 is a rear view of the binocular-like vision system of FIG.1;

[0020]FIG. 3 schematically shows the field of view generated by thebinocular-like vision system of FIG. 1;

[0021]FIG. 4 is a top view of a second embodiment of a binocular-likevision system according to the present invention;

[0022]FIG. 5 is a rear view of the binocular-like vision system of FIG.4;

[0023]FIG. 6 schematically shows the field of view generated by thebinocular-like vision system of FIG. 4;

[0024]FIG. 7 is a top view of a third embodiment of a binocular-likevision system according to the present invention;

[0025]FIG. 8 is a rear view of the binocular-like vision system of FIG.7;

[0026]FIG. 9 schematically shows the field of view generated by thebinocular-like vision system of FIG. 7;

[0027]FIG. 10 is a front view of a fourth embodiment of a binocular-likevision system according to the present invention;

[0028]FIG. 11 is a bottom view of the binocular-like vision system ofFIG. 10;

[0029]FIG. 12 schematically shows the field of view generated by thebinocular-like vision system of FIG. 10;

[0030]FIG. 13 schematically illustrates a head up display (HUD)superimposed on the field of view of FIG. 12;

[0031]FIG. 14 is a front view of the binocular-like vision system ofFIG. 10 with a mounting structure for attachment to a helmet;

[0032]FIG. 15 is a bottom view of the binocular-like vision system ofFIG. 14;

[0033]FIG. 16 shows a top view of a prior art binocular-like visionsystem and the field of view generated by the system;

[0034]FIG. 17 shows a top view of a fifth embodiment of a binocular-likevision system according to the present invention and the filed of viewgenerated by the system;

[0035]FIG. 18 is a front view of a sixth embodiment of a binocular-likevision system according to the present invention;

[0036]FIG. 19 is a top view of the binocular-like vision system of FIG.18;

[0037]FIG. 20 is a rear view of the binocular-like vision system of FIG.18;

[0038]FIG. 21 is a partially exposed top view of the binocular-likevision system of FIG. 18;

[0039]FIG. 22 shows a side view of the binocular-like vision system ofFIG. 18;

[0040]FIG. 23 shows an exposed side view of the binocular-like visionsystem of FIG. 22;

[0041]FIG. 24 is a top view of a binocular-like vision system accordingto a seventh embodiment of the present invention;

[0042]FIG. 25 is a rear view of the binocular-like vision system of FIG.24;

[0043]FIG. 26 schematically shows the field of view generated by thebinocular-like vision system of FIG. 24;

[0044]FIG. 27 is a top view of the binocular-like vision system of FIG.24 including a head up display (HUD);

[0045]FIG. 28 is a rear view of the binocular-like vision system of FIG.27;

[0046]FIG. 29 schematically shows the field of view generated by thebinocular-like vision system of FIG. 27 including a HUD unit;

[0047]FIG. 30 is a front perspective view of a modular embodiment ofthis invention mounted to a helmet visor,

[0048]FIG. 31 is a front perspective view of the modular embodiment ofthis invention in isolation;

[0049]FIG. 32 is a front perspective view of the modular embodiment ofthis invention showing the outer optical channels detached;

[0050]FIGS. 33 and 34 present top and rear plan views, respectively, ofthe modular embodiment of this invention showing the outer opticalmodules detached;

[0051]FIGS. 35 and 26 are top and rear plan views, respectively, of thismodular invention showing the outer optical channels attached;

[0052]FIG. 37 is a perspective view of an outer optical module of thisinvention shown in isolation;

[0053]FIG. 38 schematically shows the field of view generated by themodular embodiment of this invention;

[0054]FIG. 39 shows in perspective the inner left and inner rightoptical modules; and

[0055]FIG. 40 is an exploded view showing the separate module elementsforming the modular panoramic night vision assembly of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0056] Several binocular-type-viewing systems according to the presentinvention are schematically shown in FIGS. 1-23, wherein like elementsare identified by like numerals. A wide-angle lens group that provide adesired field of view of, for example, 40 degrees and can be ofconventional design, such as disclosed in U.S. Pat. No. 5,416,315, theentire contents of which are incorporated herein by reference. Theobjective optical system 66 includes approximately 2 to 7 opticalelements, such as plastic or glass lenses L, which have an effectivefocal length of approximately 21-mm, F/1.2. The lenses L of theobjective optical system are preferably spherical or aspherical indesign.

[0057] The objective optical system 66 is designed to receive light froman object being viewed at the input end 72 and to transfer an image ofthe object to the input end or photocathode side 74 of the imageintensifier tube 68.

[0058] The image intensifier tube 68 makes it possible for the observerto view an object in dark conditions by receiving the visible and/orinfrared light image of the object transferred to the input end 74thereof The image intensifier tube 68 converts the received image to anintensified visible output image in a predetermined narrow band ofwavelengths at the output end 78 of the image intensifier tube 68. Theimage intensifier tube 68 is well known in the art. For example, theimage intensifier tube 68 may include a GaAs photocathode at the inputend 74 and the binocular-like vision systems 50 of FIGS. 1-23 generallyhave an input end (72, 90) that receives light from an object and anoptical transfer system (62, 64, 86, 88) that receives the lightreceived from the input end and transfers the received light to anoutput end (80, 92) of the system, wherein light transmitted out of theoutput end forms a field of view of the object that is greater than a 60degree horizontal field of vision.

[0059] FIGS. 1-3 show one embodiment of a binocular-like vision system50 according to the present invention that operates in theabove-described manner. The vision system 50 is contained in a housingassembly 52 which has a pair of housings 54 and 56 connected to oneanother by a bridge 57 and are arranged for respectively covering theright eye 58 and the left eye 60 of an observer. A pair of eyelets 61are provided in the housings 54 and 56 to receive a strap or the like sothat the user can conveniently carry the vision system 50 around hisneck when not in use.

[0060] Each of housings 54 and 56 contain identical optical systemswhich are mirror images of each other about a plane 63 (denoted bydashed lines) that bisects the housing assembly 52 as shown in FIG. 1.Accordingly, the discussion to follow regarding the housing 54 isequally applicable to the housing 56.

[0061] As shown in FIG. 1, the housing 54 includes two separate opticalcomponents 62 and 64. The inner optical component 62 has the identicaloptical structure as the outer optical component 64. Accordingly, thediscussion to follow regarding the structure of the inner opticalcomponent 62 is equally applicable to the outer optical component 64.The inner optical component 62 includes three main opticalstructures—(1) an objective optical system 66, (2) an image intensifiertube 68 and (3) an eyepiece optical system 70. The objective opticalsystem 66 defines an input end 72 that receives light from an object.The objective optical system 66 includes output light from the imageintensifier tube 68 is emitted by a green phosphor producing a visibleband of light which is known as “P-20” light, although it will beappreciated that other image intensifier constructions could also beused.

[0062] The image intensifier tube 68 also includes a fiber optic bundle(schematically shown at 75) for transmitting bits of image data from thephotocathode input end 74 to the phosphor output end 78 thereof. Thefiber optic bundle 75 is preferably twisted in a manner well known inthe art to provide an image rotation of 180 degrees so that an uprightimage of the object will be presented to the eye of the user.

[0063] The intensified visible output image generated by the imageintensifier tube 68 is transferred to an output end 80 of the inneroptical component 62 via the eyepiece optical system 70. The lighttransmitted through the output end 80 is transmitted along the opticalaxis 84 that is aligned with the optical axis of the right eye 58. Theeyepiece optical system 70 can be of conventional design, such asdisclosed in U.S. Pat. No. 5,416,315, the entire contents of which areincorporated herein by reference. The eyepiece optical system 70includes approximately 2 to 7 optical elements, such as plastic or glasslenses L, which have an effective focal length of approximately, 21 mm,F/1.2. The lenses L of the objective optical system are preferablyspherical or aspherical in design.

[0064] In order to enlarge the field of view, an outer optical component64 is provided which also directs light from the object to the observer.As explained previously, the outer optical component 64 has the sameoptical structure as the inner optical structure 62 previouslydescribed. Like the inner optical component 62, the outer opticalcomponent 64 includes an objective optical system 66, an imageintensifier tube 68 and an eyepiece optical system 70 which operate inthe same manner as their counterparts in the inner optical component 62.Accordingly, the objective optical system 66 and the eyepiece opticalsystem 70 of the outer optical component 64 each have an effective focallength of approximately 21-mm like their counterparts in the inneroptical component 62.

[0065] The above-described outer optical component 64 operates in amanner similar to that of the inner optical component 62. The input end72 of the outer optical component 64 receives light from an object. Thereceived light is then transferred via the objective optical system 66to the image intensifier which in turn generates an intensified imagethat is received by the eyepiece optical system 70. The eyepiece opticalsystem 70 then sends the image to an output end 80 of the outer opticalcomponent 64. The light transmitted through the output end 80 travelsalong an optical axis 82 that is offset from the optical axis 84 by anangle ranging from approximately 30° to 35° and which is preferably 30degrees.

[0066] As stated previously, the inner optical component 86 for the lefteye 60 has the same structure and operates in the same manner as theinner optical component 62. Similarly, the outer optical component 88for the left eye 60 has the same structure and operates in the samemanner as the outer optical component 64. In other words, the inner andouter optical components 86 and 88 each receive light from an object atthe input ends 90 and transfer their images of the object to respectiveoutput ends 92. As shown in FIG. 1, the image from the inner opticalcomponent 86 intensifier tube 68 which is projected along an opticalaxis 94 that is aligned with the optical axis of the left eye 60 and,thus, substantially parallel to the optical axis 84. The image from theouter optical component 88 is projected along an optical axis 96 that isoffset from the optical axis 94 by an angle ranging from 30 degrees to35 degrees, preferably approximately 30 degrees. As best shown in FIG.2, the two eyepiece optical systems 70 for each of the housings 54 and56 are positioned adjacent to each other so that both images at theoutput ends 80 and 92 appear continuous without a noticeable line ofdemarcation between the exit elements of the eyepiece optical systems.With respect to the forward looking direction, the two adjacent eyepieceoptical systems for each housing 54 and 56 provide a continuoushorizontal field of view that begins about 50 degrees to the right (orto the left) and ends 15 degrees to the left (or to the right).

[0067] As shown in FIG. 1, the optical systems are in line with the lineof sight of the observer's eyes 58 and 60. In addition, as shown in FIG.2, the output ends 80 and 92 may each be offset below their respectiveinput ends 72 and 90. This is accomplished by inserting well knownmirror systems or prism systems (not shown) between the output ends 78of the image intensifier tubes 68 and the eyepiece optical components70. The apparatus also includes a well-known mechanism 98 for adjustingthe interpupillary distance between the eyepiece optical systems in thetwo housings 54 and 56 to accommodate different users.

[0068] The field of view 100 generated by the light simultaneouslytransmitted along the four optical axes 82, 84, 94, 96 to the observeris schematically shown in FIG. 3. The field of view 100 is the result ofhaving the sub-fields of view formed from each of the output ends 80 and92 overlap one another. Each of the four sub-fields of view are circularhaving a horizontal field of view of approximately 40 degrees and avertical field of view of approximately 40 degrees. The field of view100 includes two peripheral portions 102 and 104 that are separated fromone another and each portion 102 and 104 has a monocular effect on theobserver. The field of view 100 includes an overlapping central portion106 spanning approximately 30 degrees. The central portion 106 ispositioned between the monocular portions 102 and 104 and is viewed byboth eyes 58 and 60 of the observer so as to provide full depthperception and exact stereo vision in the central portion. The field ofview 100 has a vertical field of view of approximately 40 degrees and ahorizontal field of view of approximately 100 degrees.

[0069] The above described binocular-like vision system 50 of FIGS. 1-3has a mass of approximately 550 g, a micro-channel plate (MCP) pitch ofranging from 6 to 7 microns, a limiting resolution of greater than orequal to 60 LP/mm, eye relief of greater than or equal to 20 mm andsystem resolution of approximately 1.15 cy/mr min. Note that in order toproduce a distortion-free system 50, the magnifications of all fouroptical components 62, 64, 86 and 88 must be controlled to be within2.5% of each other. In addition, a coupled focus mechanism 108 isprovided to adjust the position of the input ends in the X and Ydirections so that any mismatch between two adjacent images at theoutput ends is eliminated.

[0070] Other variations of the binocular-like vision system 50 arepossible by varying the objective and eyepiece optical systems 66 and 70in numerous ways in a manner well known in the art. For example, ahorizontal field of view of—approximately 120 degrees and a verticalfield of view of approximately 50 degrees is formed by thebinocular-like vision system 50 of FIGS. 4-6. The binocular-like visionsystem 50 of FIGS. 4-6 basically has the same structure as and functionslike the system 50 previously described with respect to FIGS. 1-3 withsome minor changes to the objective optical components 66 and theeyepiece optical components 70 of the optical components 62, 64, 86 and88. The image intensifier tubes 68 are unchanged.

[0071] As with the vision system 50 of FIGS. 1-3, the inner opticalcomponents 62, 86 and the outer optical components 64 and 88 each haveidentical optical structures. The objective optical system 66 andeyepiece optical system 70 can be of conventional design, such asdisclosed in U.S. Pat. No. 5,416,315, the entire contents of which areincorporated herein by reference. The objective optical system 66includes approximately 2 to 7 optical elements, such as plastic or glasslenses L, which have an effective focal length of approximately 17-mm.The eyepiece optical system 70 includes approximately 2 to 7 opticalelements, such as plastic or glass lenses L, which have an effectivefocal length of approximately 22 mm. The lenses L of both the objectiveoptical systems 66 and the eyepiece optical systems 70 are preferablyspherical or aspherical in design.

[0072] As shown in FIG. 4, the optical axes 84 and 94 are aligned withthe optical axes of the right and left eyes 58 and 60, respectively, ofthe observer. The optical axes 82 and 96 are offset from the opticalaxes 84 and 94, respectively, by approximately 35 degrees.

[0073] The field of view 100 generated by the light simultaneouslytransmitted along the four optical axes 82, 84, 94 and 96 isschematically shown in FIG. 6. The field of view 100 is the result ofhaving the sub-fields of view formed from the output ends 80 and 92overlapping one another. The four sub-fields of view each are circularhaving a horizontal field of view of approximately 50 degrees and avertical field of view of approximately 50 degrees. In a manner similarto that shown in FIG. 3, the field of view 100 includes two monocularportions 102, 104 and a 35-degree binocular portion 106. The field ofview 100 has a vertical field of view of approximately 50 degrees and ahorizontal field of view of approximately 120 degrees.

[0074] The above described binocular-like vision system 50 of FIGS. 4-6has a mass of approximately 550 g, a limiting resolution ranging from 57to 60 LP/mm and a system resolution of approximately 0.93 cy/mr min.

[0075] The binocular-like vision system 50 of FIGS. 7-9 basically hasthe same structure as and functions like the vision system 50 previouslydescribed with respect to FIGS. 4-6 where the objective opticalcomponents 66 of the inner and outer optical components 62, 64, 86 and88 are each replaced with an identical 26 to 27 mm effective focallength objective optical component 66 sold by Night Vision Corporationunder the NOVA-8 trademark. The image intensifier tubes 68 are also soldby Night Vision Corporation under the NOVA-8 trademark.

[0076] As with the vision system 50 of FIGS. 1-6, the inner opticalcomponents 62, 86 and the outer optical components 64 and 88 each haveidentical optical structures for the objective optical systems 66, theimage intensifier tubes 68 and the eyepiece optical systems 70. Theeyepiece optical system 70 can be of conventional design, such asdisclosed in U.S. Pat. No. 5,416,315, the entire contents of which areincorporated herein by reference. The eyepiece optical system 70includes approximately 2 to 7 optical elements, such as plastic or glasslenses L, which have an effective focal length of approximately 26 to 27mm. The lenses L of both the objective optical system 66 and theeyepiece optical system 70 are preferably spherical or aspherical indesign.

[0077] As shown in FIG. 7, the optical axes 84 and 94 are aligned withthe optical axes of the right and left eyes 58 and 60, respectively, ofthe observer. The optical axes 82 and 96 are offset from the opticalaxes 84 and 94, respectively, by approximately 35 degrees.

[0078] The field of view 100 generated by the light simultaneouslytransmitted along the four optical axes 82, 84, 94 and 96 isschematically shown in FIG. 9. The field of view 100 is the result ofhaving the sub-fields of view formed from the output ends 80 and 92overlapping one another. The four sub-fields of view each are circularhaving a horizontal field of view of approximately 50 degrees and avertical field of view of approximately 50 degrees. In a manner similarto that shown in FIG. 3, the field of view 100 includes two monocularportions 102, 104 and a 35-degree binocular portion 106. The field ofview 100 has a vertical field of view of approximately 50 degrees and ahorizontal field of view of approximately 120 degrees.

[0079] The above described binocular-like vision system 50 of FIGS. 7-9has a mass of approximately 950 g, a limiting resolution of greater than60 LP/mm, a MCP pitch of 6-7 microns and a system resolution rangingfrom 1.1 to 1.4 cy/mr min.

[0080] A fourth embodiment of a binocular-like vision system accordingto the present invention is shown in FIGS. 10-15. More particularly,FIGS. 10-15 illustrate a vision visor system in which a binocular-likevision system 50 is mounted to a helmet-mounted visor 110 for use byaircraft pilots and the like. As shown in FIGS. 14-15, the visor 110 ismounted to the helmet 112 by an Aviator Night Vision Imaging System(ANVIS)-type mount 114. The mount 114 allows the visor 110 to movebetween a down position in front of the eyes of the observer during useand an up position away from the observer's face when not in use. Thevision system 50 typically includes input ports to project Head-updisplay (HUD) information and for other purposes, suitable power sourcecouplings and other structures that do not form a part of the presentinvention and are thus not described herein.

[0081] The binocular-like vision system 50 of FIGS. 10-15 generally hasthe same structure as and functions like the vision system 50 previouslydescribed with respect to the systems 50 of FIGS. 1-9 where theobjective and eyepiece optical components 66 and 70 of the inner andouter optical components 62, 64, 86 and 88 are each replaced withoptical components to give a desired field of view. As with the visionsystem 50 of FIGS. 1-9, the inner optical components 62, 86 and theouter optical components 64 and 88 each have identical opticalstructures for the objective optical systems 66, the image intensifiertubes 68 and the eyepiece optical systems 70. The objective and eyepieceoptical systems 66 and 70 can be of conventional design, such asdisclosed in U.S. Pat. No. 5,416,315, the entire contents of which areincorporated herein by reference. The objective optical system 66includes approximately optical elements, such as plastic or glass lensesL, which have an effective focal length of approximately 21.9-mm. Theeyepiece optical system 70 includes approximately optical elements, suchas plastic or glass lenses L, which have an effective focal length ofapproximately 21.9-mm. The lenses L of both the objective optical system66 and the eyepiece optical system 70 are preferably spherical oraspherical in design.

[0082] As shown in FIGS. 10-11 and 14 15, all four light components 62,64, 86 and 88 have light paths which are folded in contrast to thelinear like light paths of the binocular-like vision systems 50 of FIGS.1-9. The folded light paths are formed by a number of well known foldprisms along the optical paths and between the image intensifier tubes68 and the eyepiece optical systems 70 in a manner as described in U.S.Pat. No. 5,416,315, the entire contents of which are incorporated hereinby reference. The folded optical paths allow the apparatus to bepackaged radially close to the face along the contour of the visor 110,thereby minimizing any resulting shift in the center of gravity of totalhead-borne weight. The apparatus also provides a low profile thatminimizes any adverse aerodynamic effects that might develop underwindblast conditioning.

[0083] As shown in FIG. 11, the optical axes 84 and 94 are aligned withthe optical axes of the right and left eyes 58 and 60, respectively, ofthe observer. The optical axes 82 and 96 are offset from the opticalaxes 84 and 94, respectively, by approximately 35 degrees.

[0084] The field of view 100 generated by the light simultaneouslytransmitted along the four optical axes 82, 84, 94 and 96 isschematically shown in FIG. 12. The field of view 100 is the result ofhaving the sub-fields of view formed from the output ends 80 and 92overlapping one another. The four sub-fields of view each are circularhaving a horizontal field of view of approximately 40 degrees and avertical field of view of approximately 40 degrees. In a manner similarto that shown in FIG. 3, the field of view 100 includes two monocularportions 102, 104 and a 35-degree binocular portion 106. The field ofview 100 has a vertical field of view of approximately 40 degrees and ahorizontal field of view of approximately 100 degrees.

[0085] The above described binocular-like vision system 50 of FIGS.10-15 has a mass of approximately 550 g, a limiting resolution ofapproximately 60 LP/mm, an eye relief of 20 mm min., a system gain of3,000 min., and a system resolution of approximately 1.10 cy/mr min.

[0086] Note that each of the objective optical systems 62, 64, 86, 88 ismounted in and extends slightly through an opening provided in the visor110 and is mounted to the visor 110 by suitable bearings or the like.Although the objective optical systems 66 are fixed in position in thevisor 110, the eyepiece optical systems 70 are adjustable by adjustmentknobs 116 (FIG. 10) to match the interpupillary distances of the users.The housings carrying the objective optical systems 66 are rotatable intheir respective bearings to permit the eyepiece optical systems 70 tobe adjusted in position. Various structural details and advantageousfeatures of the visor-mounted panoramic night vision apparatus 50 ofFIGS. 10-15 are described in detail in U.S. Pat. No. 5,416,315, thedisclosure of such patent is hereby incorporated herein by reference.

[0087] The binocular-like vision system 50 of FIGS. 10-15 may alsoinclude a head-up display (HUD) unit 114 for the display of secondaryinformation such as aircraft data and symbology to the pilot and crew. Acombiner element 120 is used to superimpose HUD information onto theimage-intensified scene of the right eye 58 so that they appear in thesame plane. Thus, no change of the eye's distance adaptation is needed.The HUD information defines a rectangular region 122 of approximately 28degrees wide by 20 degrees high in the field of view 100 centered on theuser's forward-looking line of sight as shown in FIG. 13.

[0088] The HUD information is preferably provided in a contrasting color(e.g., yellow) to the green image intensified scene, and because the HUDand the image intensifier tube provide information in different colors,a dichroic combiner is used. As a result, the system will provide highbrightness for both images without requiring excessive luminance fromeither of the two sources.

[0089] The head-up display 114 in FIGS. 10-11 and 14-15 is preferably anelectroluminescent display although it may also comprise a liquidcrystal display (LCD). In this regard, reference is made to U.S. Pat.No. 5,254,852, the entire contents of which are incorporated herein byreference, which describes the use of a liquid crystal display devicefor presenting a secondary image to a user in a night imaging system.

[0090] In general, the information presented on the electronic displayis selected and formatted in a computer and is presented to the displaysubsystem as a nominal RS-170 or the like monochrome, on-off (no grayscale or with gray scale type) signal. The display panel is capable ofproducing a minimum of 480-row by 640-column to 1024×1080 (SVGA) pixelimages. Since the combiner 120 is used, the HUD image is projectedcontinuously and the user perceives yellow symbols overlaying theintensified image.

[0091] Incorporation of the HUD unit 114 into the panoramic night visionimaging apparatus 50 adds very little weight to the overall apparatus(e.g., about 65 grams); and, accordingly, the overall apparatus remainsejection safe with a minimal shift in the center of gravity of the totalheadborne weight.

[0092] In the embodiments described with reference to FIGS. 1-15,panoramic night vision imaging apparatus are described. As shown inFIGS. 17-23, the present invention may also be utilized in imagingapparatus that do not include image-intensifying means. Thebinocular-like vision systems 50 of FIGS. 17-23 generally have the samestructure as and function like the system 50 previously described withrespect to the systems 50 of FIGS. 1-15. One difference between thevision system 50 of FIGS. 1-15 and FIGS. 17-23 is that the light fromthe objective optical systems 66 will be transferred directly to theeyepiece optical systems 70 without being intensified by an imageintensifier tube in the systems of FIGS. 17-23. Like the vision systems50 of FIGS. 1-15, the vision systems of FIGS. 17-23 are able to producean enlarged field of view by using two optical components per eye. Thevision systems 50 of FIGS. 17-23 will produce a field of view that islarger than the 43-degree field of vision produced by the prior artbinoculars of FIG. 16, which are a set of Jason 7×35 PermaFocusbinoculars producing a horizontal field of view of 113 yards at adistance of 1000 yards.

[0093] The binocular-like vision systems 50 of FIGS. 17-23 include inneroptical components 62, 86 and outer optical components 64 and 88, eachcomponent having identical optical structures for the objective opticalsystems 66 and the eyepiece optical systems 70. The objective andeyepiece optical systems 66 and 70 can be of conventional design, suchas disclosed in U.S. Pat. No. 5,416,315, the entire contents of whichare incorporated herein by reference. The objective optical system 66includes approximately 2 to 7 optical elements, such as plastic or glasslenses L, which have an effective focal length of approximately 160-mm.The eyepiece optical system 70 includes approximately 2 to 7 opticalelements, such as plastic or glass lenses L, which have an effectivefocal length of approximately 25-mm. The lenses L of both the objectiveoptical system 66 and the eyepiece optical system 70 are preferablyspherical or aspherical in design.

[0094] As shown in FIGS. 17 and 21, the light from the four objectiveoptical systems 66 is transmitted to intermediate optical components 124and 126 before entering the eyepiece optical systems 70. Opticalcomponent 124 preferably is a Porro prism that rotates the image fromthe inner optical components 62 and 86 by 180 degrees so as to presentan upright image to the observer. Optical component 126 preferably is aSchmidt prism that rotates and bends the image from the outer opticalcomponents 64 and 88 so as to present an upright image.

[0095] As shown in FIGS. 17 and 21, the optical axes 84 and 94 arealigned with the optical axes of the right and left eyes 58 and 60,respectively, of the observer. The optical axes 82 and 96 are offsetfrom the optical axes 84 and 94, respectively, by approximately 35degrees.

[0096] The field of view 100 generated by the light transmitted alongthe four optical axes 82, 84, 94 and 96 shown in FIGS. 17 and 21 issimilar to that shown in FIG. 6. The field of view 100 is the result ofhaving the sub-fields of view formed from the output ends 80 and 92overlapping one another. The four sub-fields of view each are circularhaving a horizontal field of view of approximately 50 degrees and avertical field of view of approximately 50 degrees. The field of view100 includes two monocular portions 102, 104 and a 35-degree binocularportion 106. The field of view 100 has a vertical field of view ofapproximately 50 degrees and a horizontal field of view of approximately120 degrees. The binocular-like vision system 50 of FIG. 17, forexample, theoretically produces a horizontal field of view of 495 yardsat a distance of 1000 yards. The vision system 50 of FIGS. 18-23produces a horizontal field of view of 1058 feet at 1000 yards.

[0097] As in previous embodiments of FIGS. 1-15, the eyepiece opticalsystems 70 in each housing 54 and 56 are positioned adjacent to eachother so that the overall panoramic image appears continuous without anoticeable line of demarcation between the exit elements of theeyepiece.

[0098] The vision system 50 of FIGS. 18-23 differs from the visionsystem 50 of FIG. 17 in several ways. First, the outer components 64 and88 of the vision system 50 of FIGS. 18-23 each include a wedge-shapedlens 128 inserted at the input end 72. The lens 128 deflects the line ofvision entering the outer components 64 and 88 in a well-known manner.The outer components 64 and 88 further include a mirror 130 that directslight from the objective optical system 66 to a pair of wedged-shapedlenses 132 and 134 that are located adjacent to the prism 126. As shownin FIG. 21, the lenses 132 and 134 are arranged on each other to formparallel input and output sides 136 and 138, respectively. The lenses132 and 134 correct the color generated by the lens 128.

[0099] An even further embodiment of the invention is shown in FIGS.24-29 intended particularly for use in connection with flights having nohigh G considerations, such as helicopter and transport flights. In sucha setting where there is no ejection capability, there is less concernfor reduced center of gravity. A vision system 150 is shown having aninput end (172, 190) that receives light from an object and an opticaltransfer system (162, 164, 186, 188) that receives the light receivedfrom the input end and transfers the received light to an output end(180, 192) of the system, wherein light transmitted out of the outputend forms a field of view of the object that is greater than a 60-degreehorizontal field of vision. Studies by the U.S. Army suggest that themost efficient field of view for night aviation is about 80 degrees. Itis a common problem in night vision, however, that increasing the fieldof vision adversely affects resolution. The system of this inventionenhances both factors.

[0100]FIG. 24 shows the further embodiment of a binocular-like visionsystem 150 contained in a housing assembly 152 having a pair of housings154 and 156 connected to one another by a bridge 157. Housings 154 and156 are arranged for respectively covering the right eye 158 and theleft eye 160 of an observer.

[0101] Each of housings 154 and 156 contains identical optical systemswhich are mirror images of each other about a plane 163 (denoted bydashed lines) that bisects the housing assembly 152 as shown in FIGS. 24and 25. Accordingly, the discussion to follow regarding the housing 154is equally applicable to the housing 156.

[0102] As shown in FIG. 24, the housing 154 includes two separateoptical components 162 and 164. The inner optical component 162 has theidentical optical structure as the inner optical component 186 ofhousing 156. Accordingly, the discussion to follow regarding thestructure of the inner optical component 162 is equally applicable tothe optical component 186. The inner optical component 162 includesthree main optical structures—(1) an objective optical system 166, (2)an image intensifier tube 168 and (3) an eyepiece optical system 170.The objective optical system 166 defines an input end 172 that receiveslight from an object. and includes intensifier tube 168. The objectiveoptical system 166 defines input end 172 that receives light from anobject. The objective optical system 166 includes output light from theimage intensifier tube 168 that is emitted by a green phosphor producinga visible band of light which is known as “P-20” or “P-43” light,although it will be appreciated that other image intensifierconstructions could also be used.

[0103] The image intensifier tube 168 is defined by a new 16-mm format,high-resolution, tube that is lighter in weight than the conventional18-mm tube. Because four tubes are utilized in this system, as comparedto the two 18-mm tubes used in conventional design, it is critical thatthe 16-mm takes 168 be much lighter suitable tubes are available fromITT Night Vision Roanoke, Va. Tube 168 includes a fiber optic bundlewell-known in the art for transmitting bits of image data from aphotocathode input end to a phosphor output end thereof in the mannervery similar to that described above in relation with the embodimentsshown and described in relation to FIGS. 1-23. The fiber optic bundle ispreferably twisted in a manner well known in the art to provide an imagerotation of 180 degrees so that an upright image of the object will bepresented to the eye of the observer.

[0104] The intensified visible output image generated by the imageintensifier tube 168 is transferred to an output end 180 of the inneroptical component 162 via the eyepiece optical system 170. The lighttransmitted through the output end 180 is transmitted along the opticalaxis 184 that is aligned with the optical axis of the right eye 158. Theeyepiece optical system 170 can be of conventional design, such asdisclosed in U.S. Pat. No. 5,416,315, the entire contents of which areincorporated herein by reference. The eyepiece optical system 170includes approximately 2 to 7 optical elements, such as plastic or glasslenses L, which have an effective focal length of approximately, 24 mm,P/1.2. The lenses L of the objective optical system are preferablyspherical or aspherical in design.

[0105] In order to enlarge the field of view, outer optical component164 is provided to also direct light from the object to the observer.Outer optical component 164 includes an image intensifier tube and 168an optical arrangement substantially similar to the folded objectiveoptical system 66 shown and described above in relation to FIGS. 10 and11 above, which can be of a design disclosed in U.S. Pat. No. 5,416,315.Outer optical component 164 includes approximately 2 to 7 opticalelements, such as plastic or glass lenses L, which have an effectivefocal length of approximately 24-mm. The lense L of optical component164 are preferably spherical or aspherical in design. The folded opticalpath of the outer components 164 and 188 allows their respective inputends to be spaced laterally closer to the input ends of inner components162 and 186 to reduce parallax.

[0106] The above-described outer optical component 164 operates in amanner such that the input end 172 of the outer optical component 164receives light from an object. The received light is then transferredvia the objective optical system via a mirror 164 a and subsequently aprism 164 b to the input end of the image intensifier 168 defined by afield flattenen lense 168 a. Image intensifies to be 168 generates anintensified image that is received by the eyepiece optical system 170.The eyepiece optical system 170 then sends the image to an output end180 of the outer optical component 164. The light transmitted throughthe output end 180 travels along an optical axis 182 that is offset fromthe optical axis 184 of inner optical component 162 by an angle rangingfrom approximately 30 degree to 35 degree and which is preferably about30 degrees. Electrical power is provided to both tubes 168 of components162 and 164 by electrical wiper contact 169.

[0107] As stated previously, the inner optical component 186 for theleft eye 160 has the same structure and operates in the same manner asthe inner optical component 162. Similarly, the outer optical component188 for the left eye 160 has the same structure and operates in the samemanner as the outer optical component 164. In other words, the inner andouter optical components 186 and 188 of housing 156 each receive lightfrom an object at the input ends 90 and transfer their images of theobject to respective output ends 192. As shown in FIG. 24, the imagefrom the inner optical component 186 passes through an intensifier tubewhich is then projected along an optical axis 194 that is aligned withthe optical axis of the left eye 160 and, thus, substantially parallelto the optical axis 184. The image from the outer optical component 188is ultimately projected along an optical axis 196 that is offset fromthe optical axis 194 by an angle ranging from 30 degrees to 35 degrees,preferably approximately 30 degrees.

[0108] As shown in FIG. 25, the two eyepiece optical systems 170 foreach of the housings 154 and 156 are positioned adjacent to each otherso that both images at the output ends 180 and 192 appear continuouswithout a noticeable line of demarcation between the exit elements ofthe eyepiece optical systems. With respect to the forward lookingdirection, the two adjacent eyepiece optical systems for each housing154 and 156 provide a continuous horizontal field of view that beginsabout 50 degrees to the right (or to the left) and ends 15 degrees tothe left (or to the right).

[0109] As shown in FIGS. 24 and 25, the optical systems are in line withthe line of sight of the observer's eyes 158 and 160. The apparatus alsoincludes a well-known ANVIS mounting system 151 to, in a standardfashion, attach the night vision goggles of the present invention to thestandard-issue pilot's helmet. Mounting system 151 commonly includes amechanism 151 a for adjusting the interpupillary distance between theeyepiece optical systems in the two housings 54 and 56 to accommodatedifferent users. Mechanism 151 b is an adjustment dial for adjusting thefore/aft position of the system. The entire vision system 150 and bridge157 are detachably affixed to the pilot's helmet via mechanism 151 cthat is a well-known element of the ANVIS system.

[0110] The inner two objectives 166 and 186 of vision system 150 arefocus-adjustable 18 inches to infinity, and the outer optical components168 and 188 are fixed at infinity. The inner optical channels are notfolded and are designed with fast F/1.05 objective lenses. The outerchannels 168 and 188 employ a folded channel optics design with F/1.17objective lenses to reduce parallax and size. The effective focal lengthof the eyepiece is 24.0 mm, while the eye relief has been increased to30 mm. All of the mechanical adjustments currently used on the AN/AVS-6and AN/AVS-9 are the same (i.e., tilt, independent inter-pupillarydistance adjustment, up/down, fore/aft) and the like.

[0111] The field of view 200 generated by the light simultaneouslytransmitted along the four optical axes 182, 184, 194, 196 to theobserver is schematically shown in FIG. 26. The field of view 200 is theresult of having the sub-fields of view formed from each of the outputends 180 and 192 overlap one another. As shown particularly in FIG. 26,each of the four sub-fields of view are circular having a horizontalfield of view of approximately 40 degrees and a vertical field of viewof approximately 40 degrees. The field of view 200 includes twoperipheral portions 202 and 204 that are separated from one another,wherein each portion 202 and 204 has a monocular effect on the observer.The field of view 200 includes an overlapping central portion 206spanning approximately 30 degrees. The central portion 206 is positionedbetween the monocular portions 202 and 204 and is viewed by both eyes158 and 160 of the observer so as to provide full depth perception andexact stereo vision in the central portion. The field of view 200 has avertical field of view of approximately 40 degrees and a horizontalfield of view of approximately 100 degrees.

[0112] The binocular-like vision system 150 of FIGS. 27 and 28 may alsoinclude a head-up display (HUD) unit 214 for the display of secondaryinformation such as aircraft data and symbology to the pilot and crew. Abeam combiner element 220 is used to superimpose HUD information ontothe image-intensified scene of the right eye 158 so that they appear inthe same plane. Thus, no change of the eye's distance adaptation isneeded. Combiner 220 reflects 10% of the light while transmitting 90%.HUD 214 is coupled to the control system of the aircraft via cable 215.The date the aircraft controller is transmitted by way of flexiblemulti-conductor connector 215′ complying the HUD with the objective. TheHUD information defines a rectangular region 222 of approximately 29degrees wide by 20 degrees high in the field of view 200 centered on theuser's forward-looking line of sight as shown in FIG. 29.

[0113] As with the HUD system of the alternative embodiments describedabove, the HUD information is preferably provided in a contrasting color(e.g., yellow) to the green image intensified scene, and because the HUDand the image intensifier tube provide information in different colors,a dichroic or part silver type combiner is used. As a result, the systemwill provide high brightness for both images without requiring excessiveluminance from either of the two sources.

[0114] The head-up display shown in FIGS. 27 and 28 is commonly referredto as AMELD (active matrix ectroluminescent display), although it mayalso comprise a liquid crystal display (LCD). In this regard, referenceis made to U.S. Pat. No. 5,254,852, the entire contents of which areincorporated herein by reference, which describes the use of a liquidcrystal display device for presenting a secondary image to a user in anight imaging system. In general, the information presented on theelectronic display is selected and formatted in a computer and ispresented to the display subsystem as a nominal RS-170 or the likemonochrome, on-off (no gray scale or with gray scale type) visor-mountedpanoramic night vision apparatus 50 of FIGS. 10-15 are described indetail in U.S. Pat. No. 5,416,315, the disclosure of such patent ishereby incorporated herein by reference.

[0115] The binocular-like vision system 150 of FIGS. 24 and 25 has amass of approximately 600 g, a limiting resolution of approximately 64LP/mm, an eye relief of 30 mm min., a system gain of 8,000 min., and asystem resolution of approximately 1.3 cy/mr min. The binocular-likevision system 150 of FIGS. 27 and 28 including the HUD element has amass of approximately 650 g, a limiting resolution of approximately 64LP/mm, an eye relief of 30 mm min., a system gain of 7,000 min., and asystem resolution of approximately 1.3 cy/mr min.

[0116] FIGS. 30-40 present yet another embodiment of the PNVG goggle,designed so that the individual optical channels are modular and thusdetachable from each other. FIGS. 30 and 31 show the modular PNVGassembly 300 of this invention mounted on the visor 302 of an HGU-56/Phelmet 304. Modular assembly 300 may be affixed to the visor 302 byconventional means. Each of the 4 optical channels 310, 320, 330, 340 isa separately sealed and self-contained module. Removal of any singlemodule from the PNVG assembly 300 will not break any pressure seals ordegrade the optical performance of the removed module or any of theremaining modules. Electrical power and information (i.e., data signalsand the like) required by a module is provided through electricalconnector means provided between the modules. Such means could include,for example, wiper contacts 312 provided on outer optical module 310 asshown in FIG. 37, and contact pads 328, 338 provided on inner opticalmodules 320, 330, respectively, as shown in FIG. 39.

[0117] The modules include attachment means that ensures properpositioning and alignment of the adjacently mating modules. As shownbest in FIGS. 37 and 39, such attachment means may includetongue-and-groove type connectors 314, 324, 334, by which each module isslidably received by and secured to an adjacent module. While in apreferred embodiment the integral electrical connector contained withineach module (such as wiper contacts 37 and relays 328 and 338) enablesthe electrical connection between adjacent modules to be madesimultaneously with the mechanical attachment of the module, theelectrical and data connections may be made separately by way of, forexample, cable connectors or the like extending between adjacentmodules.

[0118] In addition to the modularity of the four primary opticalchannels of the PNVG assembly 300, a display 360 (i.e., HUD) and acamera 370 are modular as well. Similar to the individual opticalmodules, each of these components 360, 370 are separately sealed andself-contained modules as well. Camera 370 may be of a type usedconventionally with helmet assemblies for flight operations. Removal ofthe display 360 or camera 370 will not break any pressure seals ordegrade the performance of the removed module or of any of the remainingmodules. Again, electrical power and information (i.e., data signals andthe like) required by the camera or display is provided by electricalconnector means provided on each module.

[0119] The field of view 400 generated by the light simultaneouslytransmitted along the four optical axes of the modular components 310,320, 330, 340 is schematically shown in FIG. 38. The field of view 400is the result of having the sub-fields of view formed from the outputends of the modules overlapping one another. The field of view 400includes two monocular portions 402, 404, and a 40-degree binocularportion 406. The field of view 400 has a vertical field of view ofapproximately 40 degrees and a total horizontal field of view ofapproximately 95 degrees.

[0120] The outer optical modules are identical and interchangeable. Sucha module may be simply turned or flipped 180° to serve as the rightouter or left outer module. The right inner and left inner modules arededicated and are not interchangeable.

[0121] A significant advantage provided by the modularity of thisinvention is that one can employ if desired merely the dual-channelembodiment of this assembly as shown in FIGS. 33 and 34, comprising onlythe inner optical modules 320, 330 and the bridge 350. Such anembodiment may also include the display 360 and camera 370 if desired.This allows an end user to purchase only the dual-channel version as itsbudget permits and, as needed or as finances permit, to purchaseseparately one additional component, the universal outer optical module,to convert the dual-channel system to panoramic. This is particularlybeneficial for developing countries with limited military budgets. Thisalso allows the dual-channel assembly to be used by persons needing noor low light condition visibility but who do not need panoramiccapability, such as the aircraft or ground crew other than the pilot(s).

[0122] From an operations standpoint, each optical module operates in amanner similar to that of the non-modular optical channels discussed inthe previous embodiments. Thus, each optical module is designed toreceive light from an object being viewed at an input end 311, 321, 331,341, and to transfer an image of the object to the input end of aninternal image intensifier means (not shown). The image intensifiermeans makes it possible for the observer to view an object in darkconditions by receiving the visible and/or infrared light image of theobject transferred to the input end thereof. The image intensifier meansconverts the received image to an intensified visible output image in apredetermined narrow band of wavelengths at its output end. For example,the image intensifier means may include a GaAs photocathode at its inputend. An optical transfer system that receives the light received fromthe input end then transfers the received light to an output end 313,323, 333, 343 of each module.

[0123] Although the system and method provided by the present inventionhave been described with a preferred embodiment, those skilled in theart will understand that modifications and variations may be madewithout departing from the scope of this invention as set forth in thefollowing claims. Such modifications and variations are considered to bewithin the purview and scope of the appended claims. For example,although visor-mounted or helmet-mounted night vision imaging apparatusare described herein, the apparatus could readily be designed formounting directly to a helmet, if desired. In addition, the opticalcomponents of FIGS. 1-430 may differ from each other as long as theireffective components are able to achieve the desired parameters of thevision system, such as the desired magnification and effective focallengths of the components of the system.

What is claimed is:
 1. A modular binocular-like vision assembly forenabling an observer to view an object, said assembly comprising: atleast two optical modules including a first optical module comprising afirst input end that receives light from said object and a first outputend that receives light from said first input end, wherein said firstoutput end defines a first optical axis along which light received fromsaid first input end is transmitted; a second optical module comprisinga second input end that receives light from said object and a secondoutput end that receives light from said second input end, wherein saidsecond output end defines a second optical axis along which lightreceived from said second input end is transmitted; a bridge; andsecuring means for removably securing said first and second opticalmodules to said bridge in spaced-apart parallel fashion.
 2. The modularbinocular-like vision assembly of claim 1, wherein light transmittedfrom said at least two optical modules forms a field of view comprisinga vertical field of view of approximately 40 degrees.
 3. The modularbinocular-like vision assembly of claim 1, wherein each of said firstand second optical modules further includes image intensifier means forconverting incoming infrared and/or visible light to an intensifiedvisible image for presentation to the eyes of the observer.
 4. Themodular binocular-like vision assembly of claim 1, wherein each of saidoptical modules is individually sealed and self-contained.
 5. Themodular binocular-like vision assembly of claim 2, wherein each of saidfirst and second optical modules further includes image intensifiermeans for converting incoming infrared and/or visible light to anintensified visible image for presentation to the eyes of the observer.6. The modular binocular-like vision assembly of claim 2, wherein eachof said optical modules is individually sealed and self-contained. 7.The modular binocular-like vision assembly of claim 3, wherein each ofsaid optical modules is individually sealed and self-contained.
 8. Themodular binocular-like vision assembly of claim 3, including anindividually sealed and self-contained head-up display module removablysecured to said assembly for displaying information to the observer. 9.The modular binocular-like vision assembly of claim 6, including anindividually sealed and self-contained head-up display module removablysecured to said assembly for displaying information to the observer. 10.The modular binocular-like vision assembly of claim 7, including anindividually sealed and self-contained head-up display module removablysecured to said assembly for displaying information to the observer. 11.The modular binocular-like vision assembly of claim 9, including anindividually sealed and self-contained camera removably secured to saidassembly.
 12. The modular binocular-like vision assembly of claim 10,including an individually sealed and self-contained camera removablysecured to said assembly.
 13. A modular binocular-like vision assemblyfor enabling an observer to view an object under low light conditions,said assembly comprising: a first inner optical module comprising afirst-input end that receives light from said object and a first outputend that receives light from said first input end, wherein said firstoutput end defines a first optical axis along which light received fromsaid first input end is transmitted; a second inner optical modulecomprising a second input end that receives light from said object and asecond output end that receives light from said second input end,wherein said second output end defines a second optical axis along whichlight received from said second input end is transmitted; at least oneouter optical module comprising a third input end that receives lightfrom said object and a third output end that receives light from saidthird input end, wherein said third output end defines a third opticalaxis along which light received from said third input end istransmitted, wherein light transmitted along said first, second andthird optical axes is simultaneously transmitted from said modularbinocular-like vision assembly to said observer and forms a continuousfield of view comprising a first peripheral portion presented to an eyeof the user, and a central portion presented to both eyes of the user soas to provide full depth perception and stereo vision in said centralportion; image intensifier means operably positioned in said modules forconverting incoming infrared and/or visible light to an intensifiedvisible image for presentation to the eyes of the observer; a bridge;and securing means for removably securing said first and second opticalmodules to said bridge in spaced-apart parallel fashion.
 14. The modularbinocular-like vision assembly of claim 13, wherein each of said opticalmodules is individually sealed and self-contained.
 15. The modularbinocular-like vision assembly of claim 14, wherein light transmittedfrom said first, second and third optical modules forms a field of viewcomprising a vertical field of view of approximately 40 degrees.
 16. Themodular binocular-like vision assembly of claim 15, further comprising afourth individually sealed and self-contained outer optical modulecomprising a fourth input end that receives light from said object and afourth output end that receives light from said fourth input end,wherein said fourth output end defines a fourth optical axis along whichlight received from said fourth input end is transmitted, wherein thecombined effect of the optical modules provides a continuous field ofview which includes left and right peripheral portions presented to theleft and right eyes, respectively, of the user, and a central portionpresented to both eyes of the viewer so as to provide full depthperception and stereo vision in the central portion.
 17. The modularbinocular-like vision assembly of claim 16, wherein said continuousfield of view is at least 80 degrees in the horizontal direction, andsaid central portion of said field of view is at least 35 degrees in thehorizontal.
 18. The modular binocular-like vision assembly of claim 16,wherein said third and fourth outer optical modules are interchangeable.19. A modular panoramic vision assembly for enabling an observer to viewan object under low light conditions, said assembly comprising: a firstinner optical module comprising a first input end that receives lightfrom said object and a first output end that receives light from saidfirst input end, wherein said first output end defines a first opticalaxis along which light received from said first input end istransmitted; a second inner optical module comprising a second input endthat receives light from said object and a second output end thatreceives light from said second input end, wherein said second outputend defines a second optical axis along which light received from saidsecond input end is transmitted; a third outer optical module comprisinga third input end that receives light from said object and a thirdoutput end that receives light from said third input end, wherein saidthird output end defines a third optical axis along which light receivedfrom said third input end is transmitted, a fourth outer optical modulecomprising a fourth input end that receives light from said object and afourth output end that receives light from said fourth input end,wherein said fourth output end defines a fourth optical axis along whichlight received from said fourth input end is transmitted, wherein lighttransmitted along said first, second, third and fourth optical axes issimultaneously transmitted from said modular panoramic vision assemblyto said observer and forms a field of view comprising a vertical fieldof view of at least 35 degrees and a horizontal field of view of atleast 80 degrees; image intensifier means operably positioned in saidmodules for converting incoming infrared and/or visible light to anintensified visible image for presentation to the eyes of the observer;a bridge; and securing means for removably securing said first andsecond inner optical modules to said bridge in spaced-apart parallelfashion.
 20. The modular panoramic vision assembly of claim 19, whereineach of said optical modules is individually scaled and self-contained.21. The modular panoramic vision assembly of claim 20, includingelectrical connector means provided between said modules for permittingfree flow of electrical power and information between said modules. 22.The modular panoramic vision assembly of claim 21, wherein said moduleshaving attachment means for attaching said outer modules to said innermodules such that said modules are removably secured together in properalignment.
 23. The modular panoramic vision assembly of claim 22,wherein said third and fourth outer modules are interchangeable.
 24. Themodular panoramic vision assembly of claim 23, including an individuallysealed and self-contained head-up display module removably secured tosaid assembly for displaying information to the observer.
 25. Themodular panoramic vision assembly of claim 24, including an individuallysealed and self-contained camera removably secured to said assembly. 26.The modular panoramic vision assembly of claim 25, wherein saidelectrical connector means comprising wiper contacts and contact pads onadjacently mating modules.
 27. The modular panoramic vision assembly ofclaim 26, wherein said attachment means comprising tongue-and-groovetype connectors.